Effects of antidepressant treatment on heart rate variability in major depression: a quantitative review

Transcriptome networks and physiology related to cardiac function and motor activity are perturbed in larval zebrafish (Danio rerio) following exposure to the antidepressant citalopram

Citalopram is a selective serotonin reuptake inhibitor (SSRI) used to treat depression and is often detected in aquatic environments. Here, we measured the acute toxicity of citalopram at environmentally relevant concentrations to zebrafish embryos/larvae and utilized RNA-seq to reveal potential mechanisms of toxicity. We also assessed behavioral outcomes in larval zebrafish. Zebrafish embryos were exposed continuously to embryo rearing medium (ERM), or one concentration of 0.1, 1, 10, 100, and 1000 μg/L citalopram for 7 days post-fertilization (dpf). No acute toxicity was noted for citalopram over 7-days in developing zebrafish, nor were there any effects on hatch rates; however, exposure resulted in a dose-dependent decrease in heart rate at 2 dpf. Reactive oxygen species were also increased in 7-day old larvae zebrafish exposed to 100 μg/L citalopram. There were 29 genes differentially expressed in fish exposed to 10 μg/L citalopram [FDR <0.05] and 79 genes differentially expressed in fish exposed to 1000 μg/L citalopram [FDR <0.05]. In the 1000 μg/L citalopram treatment, there were several transcripts downregulated related to muscle function, including myhz2, myhz1, and myom1. Twenty-five gene set pathways were shared between exposure concentrations including 'IL6 Expression Targets', 'Thyroid Stimulating Hormone (TSH) Resistance in Congenital Hypothyroidism', and 'GFs/TNF - > Ion Channels.' Enrichment of KEGG pathways revealed that 1000 μg/L citalopram altered processes related to the proteosome and cardiac muscle contractions. Larval zebrafish at 7 dpf showed hypoactivity with exposure to ≥10 μg/L citalopram. This may be related to the downregulation of transcripts involved in muscle function. Overall, our results show that citalopram as a pharmaceutical pollutant may have an adverse influence on aquatic species' ability to survive by reducing their abilities to elude predators (e.g. cardiac output, locomotor activity). This study improves mechanistic understanding of the potential harm citalopram may cause fish and contributes to environmental risk assessments for SSRIs in aquatic species.

Childhood Family Stress and Women's Health: Parasympathetic Activity as a Risk and Resiliency Factor

Childhood family stress (CFS) exacerbates risk for physical health problems across the lifespan. Health risks associated with CFS are particularly relevant for women who tend to endorse more CFS than men. Importantly, some evidence suggests that individuals may vary in their susceptibility to CFS. Parasympathetic activity, which helps to regulate automatic bodily activity (e.g., breathing, digestion), has been proposed to represent a marker of plasticity to environmental exposure. However, no research to date has tested whether parasympathetic activity may modulate the impact of early adversity on health. We examined whether parasympathetic activity would moderate the link between CFS and health complaints in a sample of 68 undergraduate women (Mean age = 19.44). Participants self-reported CFS and health complaints. Parasympathetic activity was indexed using high-frequency heart rate variability (HF-HRV) and was evaluated by measuring changes in HF-HRV in response to and following a laboratory-based stress induction. Multiple regression analyses indicated that CFS was significantly associated with more health complaints. Further, HF-HRV in response to stress and during recovery relative to baseline significantly moderated relationship between CFS and health complaints. Specifically, more CFS was significantly associated with more health complaints among women who showed mean or greater decreases in HF-HRV in response to stress. Additionally, lower levels of CFS were associated with fewer health complaints among women who showed mean or greater HF-HRV during recovery relative to baseline. Findings highlight the importance of parasympathetic activity in modulating stress-health links.

Heart-Brain Axis: A Narrative Review of the Interaction between Depression and Arrhythmia

Arrhythmias and depression are recognized as diseases of the heart and brain, respectively, and both are major health threats that often co-occur with a bidirectional causal relationship. The autonomic nervous system (ANS) serves as a crucial component of the heart-brain axis (HBA) and the pathway of interoception. Cardiac activity can influence emotional states through ascending interoceptive pathways, while psychological stress can precipitate arrhythmias via the ANS. However, the HBA and interoception frameworks are often considered overly broad, and the precise mechanisms underlying the bidirectional relationship between depression and arrhythmias remain unclear. This narrative review aims to synthesize the existing literature, focusing on the pathological mechanisms of the ANS in depression and arrhythmia while integrating other potential mechanisms to detail heart-brain interactions. In the bidirectional communication between the heart and brain, we emphasize considering various internal factors such as genes, personality traits, stress, the endocrine system, inflammation, 5-hydroxytryptamine, and behavioral factors. Current research employs multidisciplinary knowledge to elucidate heart-brain relationships, and a deeper understanding of these interactions can help optimize clinical treatment strategies. From a broader perspective, this study emphasizes the importance of considering the body as a complex, interconnected system rather than treating organs in isolation. Investigating heart-brain interactions enhance our understanding of disease pathogenesis and advances medical science, ultimately improving human quality of life.

Vortioxetine's impact on the autonomic nervous system in depressed children and adolescents: analysis of the heart rate variability

Relationship between depressive disorder and autonomic nervous system has been already discussed. Reduced emotional regulation is supposed to be associated with prefrontal hypofunction and subcortical hyperactivity. The aim of this study was to determine the effect of vortioxetine on heart rate variability (HRV), a parameter of cardiac autonomic regulation, in depressed hospitalized paediatric patients and assess the clinical effectiveness of the drug in this population. We performed repeated polysomnography analyses at admission and after a short treatment in hospital (15.2 days on average) and measured various HRV parameters (RRi, pNN50, RMSSD, LF-HRV, HF-HRV) during wakefulness, N3 and REM sleep stages. Out of 27 study subjects, 67% have improved depression symptoms as well as anxiety and subjective sleep quality after short vortioxetine treatment. We have found a significant decrease in parasympathetic parameters pNN50, RMSSD and HF-HRV during N3 sleep phase, though not exclusively among vortioxetine responders. The anticipated increase in cardiovagal regulation after vortioxetine treatment was not demonstrated in this pilot study, possibly due to the drug's multimodal mechanism and impact on the nucleus tractus solitarii, particularly its antagonism on 5HT-3 receptors. Application of selective drugs could further explain the effect of vortioxetine on HRV in depressed patients.

Reliability of five-minute vs. one-hour heart rate variability metrics in individuals with spinal cord injury

Background

A previous study showed low reliability of 1-h HRV outcomes in participants with spinal cord injury (SCI), but it was not certain whether the low reliability was due to the unrestricted activity of participants. We aimed to investigate test-retest reliability of HRV metrics in individuals with SCI using a 1-h measurement in a supine position.

Methods

Individuals with SCI underwent two sessions of 1-h recording of the time between consecutive R waves (RR-intervals) in a supine position. HRV outcomes were obtained from a single 5-min data segment and for the full 1-h recording. HRV parameters of interest were: standard deviation of all normal-to-normal R-R intervals (SDNN) and square root of the mean of the squared differences between successive R-R intervals (RMSSD) (time domain); and high frequency power (HF), low frequency power (LF), very low frequency power (VLF), ultra-low frequency power (ULF) and total power (TP) (frequency domain). Relative reliability was assessed by intraclass correlation coefficient (ICC). Absolute reliability was assessed by coefficient of variation (CV) and Bland-Altman limits of agreement (LoA).

Results

Data from 37 individuals (14 with tetraplegia and 23 with paraplegia) were included. Relative reliability was higher for the 1-h (ICCs ranged from 0.13-0.71) than for the 5-min duration (ICCs ranged from 0.06-0.50) in the overall SCI group for all HRV metrics. Participants with tetraplegia had lower relative reliability compared to participants with paraplegia in all HRV metrics for the 5-min duration (ICCs ranged from -0.01-0.34 vs. 0.21-0.57). For the 1-h duration, participants with paraplegia showed higher relative reliability than participants with tetraplegia in all HRV metrics (ICCs ranged from 0.18-0.79 vs. 0.07-0.54) except TP (ICC 0.69 vs. 0.82). In terms of absolute reliability, the CVs and LoAs for the 1-h duration were better than for the 5-min duration. In general, time domain metrics showed better reliability than frequency domain metrics for both durations in participants with tetraplegia and paraplegia. The lowest CV and narrowest 95% LoA were found for SDNN in 5-min and 1-h durations overall and in both lesion levels.

Conclusions

The supine position did not provide better reliability compared to unrestricted activity in participants with SCI. HRV analysis using a 5-min duration is of limited value in SCI due to poor reliability. For the 1-h analysis duration, interpretation of the reliability of HRV varies according to lesion level: it is recommended to take lesion level into account when interpreting reliability measures.

Test-retest reliability of short- and long-term heart rate variability in individuals with spinal cord injury

STUDY DESIGN

Cross-sectional.

OBJECTIVES

To investigate test-retest reliability of heart rate variability (HRV) metrics in SCI without restriction of activity over long (24-h) and shorter durations (5-min, 10-min, 1-h, 3-h and 6-h).

SETTINGS

University hospital in Khon Kaen, Thailand.

METHODS

Forty-five participants (11 with tetraplegia and 34 with paraplegia) underwent two 24-h recordings of RR-intervals to derive time and frequency HRV metrics. Relative reliability was assessed by intraclass correlation coefficient (ICC) and absolute reliability by coefficient of variation (CV) and Bland-Altman limits of agreement (LoA).

RESULTS

For 5- and 10-min durations, eight of eleven HRV metrics had moderate to excellent reliability (ICC 0.40-0.76); the remaining three were poor (ICC < 0.4). HRV values from 1-h and 3-h durations showed moderate to excellent reliability (ICC of 0.46-0.81), except for 1-h reliability of ULF and TP (ICC of 0.06 and 0.30, respectively). Relative reliability was excellent (ICC of 0.77-0.92) for 6-h and 24-h durations in all HRV metrics. Absolute reliability improved as recording duration increased (lower CVs and narrower LoAs). Participants with high AD risk (SCI level at or above T6) showed lower test-retest reliability of HF and LF values than participants with low AD risk.

CONCLUSION

Relative reliability of HRV was excellent for 6-h and 24-h. The best absolute reliability values were for 24-h duration. Time-domain outcomes were more reliable than frequency domain outcomes. Participants with high risk of AD, particularly those with tetraplegia, showed lower reliability, especially for HF and LF.

Cardiovascular autonomic neuropathy in patients with type 2 diabetes with and without sensorimotor polyneuropathy

BACKGROUND AND AIMS

Cardiovascular autonomic neuropathy (CAN) in patients with diabetes is associated with poor prognosis. We aimed to assess signs of CAN and autonomic symptoms and to investigate the impact of sensorimotor neuropathy on CAN by examining type 2 diabetes patients with (DPN [distal sensorimotor polyneuropathy]) and without distal sensorimotor polyneuropathy (noDPN) and healthy controls (HC). Secondarily, we aimed to describe the characteristics of patients with CAN.

METHODS

A population of 374 subjects from a previously described cohort of the Danish Centre for Strategic Research in Type 2 Diabetes (DD2) were included. Subjects were examined with the Vagus™ device for the diagnosis of CAN, where two or more abnormal cardiovascular autonomic reflex tests indicate definite CAN. Autonomic symptoms were assessed with Composite Autonomic Symptom Score 31 (COMPASS 31) questionnaire. DPN was defined according to the Toronto consensus panel definition.

RESULTS

Definite CAN was present in 22% with DPN, 7% without DPN and 3% of HC, and 91% of patients with definite CAN had DPN. Patients with DPN and definite CAN reported higher COMPASS 31 scores compared to patients with noDPN (20.0 vs. 8.3, p < 0.001) and no CAN (22.1 vs. 12.3, p = 0.01). CAN was associated with HbA1c and age in a multivariate logistic regression analysis but was not associated with IEFND or triglycerides.

INTERPRETATION

One in five patients with DPN have CAN and specific CAN characteristics may help identify patients at risk for developing this severe diabetic complication. Autonomic symptoms were strongly associated with having both DPN and CAN, but too unspecific for diagnosing CAN.

When Heart Beats Differently in Depression: Review of Nonlinear Heart Rate Variability Measures

BACKGROUND

Disturbed heart dynamics in depression seriously increases mortality risk. Heart rate variability (HRV) is a rich source of information for studying this dynamics. This paper is a meta-analytic review with methodological commentary of the application of nonlinear analysis of HRV and its possibility to address cardiovascular diseases in depression.

OBJECTIVE

This paper aimed to appeal for the introduction of cardiological screening to patients with depression, because it is still far from established practice. The other (main) objective of the paper was to show that nonlinear methods in HRV analysis give better results than standard ones.

METHODS

We systematically searched on the web for papers on nonlinear analyses of HRV in depression, in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 framework recommendations. We scrutinized the chosen publications and performed random-effects meta-analysis, using the esci module in jamovi software where standardized effect sizes (ESs) are corrected to yield the proof of the practical utility of their results.

RESULTS

In all, 26 publications on the connection of nonlinear HRV measures and depression meeting our inclusion criteria were selected, examining a total of 1537 patients diagnosed with depression and 1041 healthy controls (N=2578). The overall ES (unbiased) was 1.03 (95% CI 0.703-1.35; diamond ratio 3.60). We performed 3 more meta-analytic comparisons, demonstrating the overall effectiveness of 3 groups of nonlinear analysis: detrended fluctuation analysis (overall ES 0.364, 95% CI 0.237-0.491), entropy-based measures (overall ES 1.05, 95% CI 0.572-1.52), and all other nonlinear measures (overall ES 0.702, 95% CI 0.422-0.982). The effectiveness of the applied methods of electrocardiogram analysis was compared and discussed in the light of detection and prevention of depression-related cardiovascular risk.

CONCLUSIONS

We compared the ESs of nonlinear and conventional time and spectral methods (found in the literature) and demonstrated that those of the former are larger, which recommends their use for the early screening of cardiovascular abnormalities in patients with depression to prevent possible deleterious events.

A recent suicide attempt and the heartbeat: Electrophysiological findings from a trans-diagnostic cohort of patients and healthy controls

Suicidal behavior is influenced by a multitude of factors, making prediction and prevention of suicide attempts (SA) a challenge. A useful tool to uncover underlying pathophysiology or propose new therapy approaches are biomarkers, especially within the context of point-of-care tests. Heart rate variability (HRV) is a well-established biomarker of mental health, and measures the activity of the sympathetic and parasympathetic nervous system (PNS). Previous studies reported a correlation between lower PNS activity and suicidality. However, most studies involved participants from a healthy population, patients without history of suicide attempts, or patients with a single diagnosis. 52 in-patients with a recent suicide attempt (<6 months), and 43 controls without history of SA or psychiatric diagnoses confirmed study participation. The included patients age ranged between 18 and 65 years, 65% had psychiatric comorbidities. Patients with dementia, cognitive impairments, acute psychosis, chronic non suicidal self-harming behavior, or current electroconvulsive therapy were excluded. A 15-min resting state electrocardiography was recorded with two bipolar electrodes attached to the right and left insides of the wrists. The multiple regression analyses showed lower parasympathetic, and higher sympathetic activity in patients compared to controls. Partial correlation found a positive trend result between self-reported suicidality and the very low frequency band. ROC curve analysis revealed an acceptable to excellent clinical accuracy of HRV parameters. Therefore, HRV parameters could be reliable discriminative biomarkers between in-patients with a recent SA and healthy controls. One limitation is the lack of a control group consisting of in-patients without life-time suicidal ideation or attempts.

The Effect of Antipsychotics and Their Combinations with Other Psychotropic Drugs on Electrocardiogram Intervals Other Than QTc among Jordanian Adult Outpatients

The ECG changes produced by antipsychotics and other psychotropic medications are studied mostly regarding QTc interval prolongation. This study aimed to investigate ECG changes beyond long QTc interval produced by psychotropic medications. A cross-sectional study was conducted to assess the effect of these agents on RR, PR, TpTe intervals and TpTe/QT ratio among Jordanian outpatients. The RR interval was significantly shorter among patients on TCAs versus those not receiving TCAs and among patients on polytherapy versus those on monotherapy (p < 0.05 for both comparisons), when adjusted for age, gender, BMI, caffeine intake, smoking, presence of diabetes mellitus, cardiovascular disease and medications known to produce heart rate changes. Positive correlations were found between the PR interval and age in patients treated with SGAs, SSRIs, citalopram, polytherapy and in the total sample (p < 0.01 for all). Inverse correlations were found between the RR interval and the number of psychotropic medications among patients treated with SSRIs and in the whole study sample (p < 0.01 for both). In conclusion, various ECG changes beyond QTc interval prolongation are observed in patients on antipsychotics and other psychotropic medications, in those on polytherapy. It is recommended to obtain an ECG before starting patients on psychotropic drugs known to produce electrocardiographic changes and their combinations.

Cardiac vagal activity is associated with gut-microbiome patterns in women-An exploratory pilot study

Introduction

A functional reciprocity between the gut microbiome and vagal nerve activity has been suggested, however, human studies addressing this phenomenon are limited.

Methods

Twenty-four-hour cardiac vagal activity (CVA) was assessed from 73 female participants (aged 24.5 ± 4.3 years). Additionally, stool samples were subjected to 16SrRNA gene analysis (V1–V2). Quantitative Insights Into Microbial Ecology (QIIME) was used to analyse microbiome data. Additionally, inflammatory parameters (such as CRP and IL-6) were derived from serum samples.

Results

Daytime CVA correlated significantly with gut microbiota diversity (r_sp = 0.254, p = 0.030), CRP (r_sp = −0.348, p = 0.003), and IL-6 (r_sp = −0.320, p = 0.006). When the group was divided at the median of 24 h CVA (Mdn = 1.322), the following features were more abundant in the high CVA group: Clostridia (Linear discriminant analysis effect size (LDA) = 4.195, p = 0.029), Clostridiales (LDA = 4.195, p = 0.029), Lachnospira (LDA = 3.489, p = 0.004), Ruminococcaceae (LDA = 4.073, p = 0.010), Faecalibacterium (LDA = 3.982, p = 0.042), Lactobacillales (LDA = 3.317, p = 0.029), Bacilli (LDA = 3.294, p = 0.0350), Streptococcaceae (LDA = 3.353, p = 0.006), Streptococcus (LDA = 3.332, p = 0.011). Based on Dirichlet multinomial mixtures two enterotypes could be detected, which differed significantly in CVA, age, BMI, CRP, IL-6, and diversity.

Conclusions

As an indicator of gut-brain communication, gut microbiome analysis could be extended by measurements of CVA to enhance our understanding of signalling via microbiota-gut-brain-axis and its alterations through psychobiotics.

δEPCD: the electrophysiologic coefficient of depressiveness

Despite research advances, recently identified biological markers for depression are either non-specific or impractical in daily clinical practice. Hence, we aim to identify a novel biomarker: δ_EPCD, the electrophysiologic coefficient of depressiveness. δ_EPCD must be sensitive and specific to the vulnerability towards depression. It should also detect the presence of a depressive clinical state and be able to quantify its severity. Moreover, it should be easily accessible and cost-effective. Accordingly, combining high-frequency heart rate variability (HF-HRV), which reflects a reduction in vagal tone, and tryptophan metabolism, which influences serotonin synthesis pathway, may have a good diagnostic and prognostic accuracy in depression. δ_EPCD is the multiplication of the intrinsic difference between state 0 (rest) and state 1 (exposure to stress) of HF-HRV and the plasma concentration ratio between quinolinic acid and kynurenine. δ_EPCD theoretically fluctuates between -1000 and 0 where being closer to 0 signifies no vulnerability to depression. Individuals with a score between -16.7 and -167 have a high vulnerability to depression. Finally, individuals with a δ_EPCD closer to -1000 have the most severe forms of depression. δ_EPCD is theoretically conceived to be easy to assess and monitor which makes it a candidate for further evaluation of reliability and validity.CLINICAL SIGNIFICANCEDepression is currently diagnosed based on emotional and behavioural symptoms; however there is currently a rising interest in the field of neurobiological markers that could improve diagnostic accuracy.Many current biological approaches are primarily based on single neurobiological markers that are either non-specific or impractical in daily clinical practice.Among other neurological effects, depression may modify the parasympathetic nervous system tone and disturb the tryptophan metabolism.The electrophysiological coefficient of depressiveness δ_EPCD combines heart rate variability (HRV) and tryptophan metabolism to reflect the intrinsic individual vulnerability towards depression and the inherent severity of an index depressive disorder.δ_EPCD is the intrinsic difference between state 0 (without stress) and state 1 (exposed to a stressful task) of the high-frequency heart rate variability multiplied by the intrinsic difference between both states, e.g. state 0 and 1, of the plasma concentration ratio of quinolinic acid over kynurenine.

Pathophysiological mechanisms of bradycardia in patients with anorexia nervosa

BACKGROUND

The purpose of this investigation was to examine heart rate variability (HRV), interbeat interval (IBI), and their interrelationship in healthy controls, bradycardic hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) mutation carriers, and patients with anorexia nervosa (AN). We tested the hypothesis that neural mechanisms cause bradycardia in patients with AN. Therefore, we assumed that saturation of the HRV/IBI relationship as a consequence of sustained parasympathetic control of the sinus node is exclusively detectable in patients with AN.

METHODS

Patients with AN between the ages of 12 and 16 years admitted to our hospital due to malnutrition were grouped and included in the present investigation (N = 20). A matched-pair group with healthy children and adolescents was created. Groups were matched for age and sex. A 24-hour Holter electrocardiography (ECG) was performed in controls and patients. More specifically, all patients underwent two 24-hour Holter ECG examinations (admission; refeeding treatment). Additionally, the IBI was recorded during the night in HCN4 mutation carriers (N = 4). HRV parameters were analyzed in 5-minute sequences during the night and plotted against mean corresponding IBI length. HRV, IBI, and their interrelationship were examined using Spearman's rank correlation analyses, Mann-Whitney U tests, and Wilcoxon signed-rank tests.

RESULTS

The relationship between IBI and HRV showed signs of saturation in patients with AN. Furthermore, signs of HRV saturation were present in two HCN4 mutation carriers. In contrast, signs of HRV saturation were not present in controls.

CONCLUSIONS

The existence of HRV saturation does not support the existence of parasympathetically mediated bradycardia. Nonneural mechanisms, such as HCN4 downregulation, may be responsible for bradycardia and HRV saturation in patients with AN.

Assessment of psychiatric comorbidities and serotonergic or noradrenergic medication use on blood pressure using 24-hour ambulatory blood pressure monitoring

In this study, the authors aimed to assess both nighttime and daytime blood pressure (BP) variability using 24-hour ambulatory BP monitoring (ABPM) in persons with and without psychiatric conditions and with or without selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) treatment. In this retrospective study, patients who underwent psychiatric evaluation and ABPM within 6 months of each other between January 1, 2012 and December 31, 2017 were identified using billing data. Participants were divided into three groups-participants with no psychiatric diagnosis and no psychiatric medicine (-Diagnosis/-Medication), those with psychiatric diagnosis and on SSRIs/SNRIs (+Diagnosis/+Medication), and psychiatric diagnosis but no psychiatric medications (+Diagnosis/-Medication). Day and nighttime systolic and diastolic BPs were compared between groups controlling for relevant variables using multivariable linear regression models. A total of 475 participants met inclusion criteria including 135 in the -Diagnosis/-Medication group, 232 in the +Diagnosis/+Medication group, and 108 in the +Diagnosis/-Medication group. In adjusted multivariable analysis, the +Diagnosis/+Medication group had higher nighttime systolic BP (median 120 vs 110 mm (Hg); p = .01) and nighttime diastolic BP (median 68 vs 63 mm (Hg); p = .006) as compared to -Diagnosis/-Medication. No statistically significant differences in BPs between the -Diagnosis/-Medication and +Diagnosis/-Medication groups were observed, after adjustment. Use of SSRIs/SNRIs was associated with significantly higher nocturnal systolic and diastolic BP among patients with psychiatric diagnosis using SSRIs/SNRIs but not associated with psychiatric diagnosis without SSRI/SNRI use. SSRIs/SNRIs use may be associated with higher BP levels and this merits future prospective studies using ABPM to assess day and nighttime BP changes with SSRIs/SNRIs use.

Perioperative Implications of the 2020 American Heart Association Scientific Statement on Drug-Induced Arrhythmias-A Focused Review

The recently released American Heart Association (AHA) scientific statement on drug-induced arrhythmias discussed medications commonly associated with bradycardia, supraventricular tachycardias, and ventricular arrhythmias. The foundational data for this statement were collected from general outpatient and inpatient populations. Patients undergoing surgical and minimally invasive treatments are a unique subgroup, because they may experience hemodynamic changes associated with anesthesia and their procedure, receive multiple drug combinations not given in either inpatient or outpatient settings, or experience postprocedural inflammatory syndromes. Accordingly, the generalizability of the AHA scientific statement to this perioperative population is unclear. This focused review highlights important aspects of the new AHA scientific statement and their application to the perioperative setting. The authors review medications frequently encountered and given by anesthesiologists and their risk of drug-induced arrhythmias and discuss common anesthetic and adjunctive medications and their associated risks of bradycardia, atrial fibrillation, torsades de pointes, and drug-induced Brugada syndrome. In many instances, the risk of arrhythmia reported by the AHA scientific statement in the general population appeared to be higher than found in perioperative arenas. Furthermore, the authors discuss the arrhythmia risk of additional medications commonly ordered or administered by anesthesiologists that are not included in the AHA scientific statement. As patient and procedural complexity increases and novel anesthetic combinations propagate, further research and observational studies will be required to delineate further perioperative risks for drug-induced arrhythmia.

The Heart-Brain Connection in Depression: Can it inform a personalised approach for repetitive transcranial magnetic stimulation (rTMS) treatment?

There is growing enthusiasm into the frontal-vagal network theory of major depressive disorder (MDD) and the potential role of a frontal-vagal network in the therapeutic mechanism of repetitive transcranial magnetic stimulation (rTMS) treatment for MDD. A review of the autonomic nervous system (ANS) in MDD and its role in antidepressant treatment for MDD is timely. The literature supports the well-established notion of ANS dysfunction in MDD and the benign effect of selective serotonin reuptake inhibitors, but not tricyclic antidepressants, on perturbed ANS function in MDD. Notwithstanding, there is some evidence that ANS measures have the capacity to inform response to antidepressant medication treatment. While there is a paucity of studies on the effects of rTMS on the ANS, critically, there is preliminary support that rTMS may alleviate ANS dysfunction in MDD and that ANS measures are associated with rTMS treatment response. These observations are consistent with the frontal-vagal theory of depression and the emerging literature on the use of ANS measures for personalising and optimising rTMS treatment of MDD.

Predictive value of heart rate in treatment of major depression with ketamine in two controlled trials

OBJECTIVE

Ketamine has been shown to be effective in treatment of episodes of major depressive disorder (MDD). This controlled study aimed to analyse the predictive and discriminative power of heart rate (HR) and heart rate variability (HRV) for ketamine treatment in MDD.

METHODS

In 51 patients, HR and HRV were assessed at baseline before and during ketamine infusion and 24 hours post ketamine infusion. Montgomery-Åsberg Depression Rating Scale (MADRS) was used to assess changes of depressive symptoms. A 30% or 50% reduction of symptoms after 24 hours or within 7 days was defined as response. A linear mixed model was used for analysis.

RESULTS

Ketamine infusion increased HR and HRV power during and after infusion. Responders to ketamine showed a higher HR during the whole course of investigation, including at baseline with medium effect sizes (Cohen's d = 0.47-0.67). Furthermore, HR and HRV power discriminated between responders and non-responders, while normalized low and high frequencies did not.

CONCLUSION

The findings show a predictive value of HR and HRV power for ketamine treatment. This further underlines the importance of the autonomous nervous system (ANS) and its possible malfunctions in MDD.

SIGNIFICANCE

The predictive power of HR and HRV markers should be studied in prospective studies. Neurophysiological markers could improve treatment for MDD via optimizing the choice of treatments.

Association Between Depression, Lung Function, and Inflammatory Markers in Patients with Asthma and Occupational Asthma

OBJECTIVE

Depression is associated with autonomic and immune dysregulation, yet this remains poorly explored in asthma. We assessed associations between depressive disorder, lung function, and inflammatory markers in patients under investigation for occupational asthma (OA).

METHODS

One hundred twelve patients under investigation for OA (60% men) underwent a psychiatric interview to assess depressive disorder, and spirometry, a methacholine test, sputum induction, and specific inhalation challenge (SIC) to assess OA. Blood and sputum inflammatory markers were assessed.

RESULTS

There was a statistically significant association between depressive disorder (P = 0.0195) and forced expiratory volume in 1 second (FEV1) responses, with the drop in FEV1 post-SIC smaller in patients with OA and depression, versus OA with no depression (P < 0.001).

CONCLUSION

The presence of depressive disorder may influence FEV1 in patients with OA, which may be via autonomic pathways. However, further studies are warranted in order to determine the mechanisms that underlie these effects.

Exploring the effectiveness of a specialized therapy programme for burnout using subjective report and biomarkers of stress

The increasing prevalence of stress-related disorders such as burnout urges the need for specialized treatment approaches. Programmes combining psychotherapy and regenerative interventions emerge to be the most successful. However, evaluated therapy programmes are scarce and usually involve subjective symptom quantification without consideration of physiologic parameters. The aim of the present exploratory, single-group study was the multimodal investigation of the effectiveness of a specialized holistic therapy programme by assessing symptoms and biological markers of chronic stress. Seventy-one in-patients (39 men/32 women; age 46.8 ± 9.9 years) of a specialized burnout ward with the additional diagnosis of burnout (Z73.0) in conjunction with a main diagnosis of depressive disorder (F32 or F33) according to the International Classification of Diseases (ICD)-10 were included in the study. In addition to symptomatology, the stress-responsive biomarkers heart rate variability (HRV) and serum brain-derived neurotrophic factor (BDNF) were measured in patients at admittance to and discharge from the burnout ward applying a 6-week specialized treatment programme. At discharge, patients showed a significant reduction of symptom burden and a significant increase in serum BDNF, while HRV remained unchanged. The findings implicate that the therapy programme may have beneficial effects on symptomatology and neuroplasticity of patients with burnout. As therapy was often supplemented by psychopharmacological treatment, a relevant influence of antidepressant medication especially on BDNF has to be considered.

Cardiac autonomic tone, plasma BDNF levels and paroxetine response in newly diagnosed patients of generalised anxiety disorder

Objective: The study examined the effect on cardiac autonomic tone via heart rate variability (HRV), brain derived neurotrophic factor (BDNF) in newly diagnosed generalised anxiety disorder (GAD) cases with paroxetine-controlled release (PX) CR intervention.Methods: Fifty GAD cases using DSM-5 criteria, matched with healthy controls (HC) were assessed with clinical measures (Hamilton Anxiety Scale (HAM-A), Clinical Global Impression- Severity Scale (CGI-Severity), General Health Questionnaire -12 (GHQ-12), HRV, plasma BDNF levels initially and 6 weeks postintervention with paroxetine CR.Results: HRV parameters were significantly lower in GAD vs HC at baseline for standard deviation of normal to normal intervals (SDNN) and proportion of differences in consecutive NN intervals that are longer than 50 ms (pNN50). Significantly higher plasma BDNF levels were noted between HC versus GAD at baseline. Postintervention HAM-A, CGI scores, GHQ-12 item scores showed significant reduction. Significant differences also noted in square root of mean squared difference of successive NN intervals (RMSSD), (SDNN), pNN50 and in plasma BDNF levels after intervention within GAD group. Significant negative correlation observed between HAM-A scores and SDNN parameter after taking PX CR in GAD.Conclusion: GAD showed cardiac autonomic dysfunction, lowered plasma BDNF levels and their improvement with paroxetine CR.Key messageGAD is associated with significantly lower HRV, suggestive of cardiac autonomic dysfunction and lowered plasma BDNF levels, an indicator of stress.Therapeutic intervention with Paroxetine in GAD patients showed clinically significant improvement reflecting restoration of the cardiac autonomic tone and BDNF levels, thus implying their role as potential biomarkers.

The association of depression and anxiety with cardiac autonomic activity: The role of confounding effects of antidepressants

BACKGROUND

Depression and anxiety may unfavorably impact on cardiac autonomic dysregulation. However, it is unclear whether this relationship results from a causal effect or may be attributable to confounding factors. We tested the relationship between depression and anxiety with heart rate (HR) and heart rate variability (HRV) across a 9-year follow-up (FU) period and investigated possible confounding by antidepressant use and genetic pleiotropy.

METHODS

Data (no. of observations = 6,994, 65% female) were obtained from the longitudinal Netherlands Study of Depression and Anxiety, with repeated waves of data collection of HR, HRV, depression, anxiety, and antidepressant use. Summary statistics from meta-analyses of genome-wide association studies were used to derive polygenic risk scores of depression, HR, and HRV.

RESULTS

Across the 9-year FU, generalized estimating equations analyses showed that the relationship between cardiac autonomic dysregulation and depression/anxiety rendered nonsignificant after adjusting for antidepressant use. A robust association was found between antidepressant use (especially tricyclic antidepressants, selective serotonin, and noradrenalin reuptake inhibitors) and unfavorable cardiac autonomic activity across all waves. However, no evidence was found for a genetic correlation of depression with HR and HRV, indicating that confounding by genetic pleiotropy is minimal.

CONCLUSIONS

Our results indicate that the association between depression/anxiety and cardiac autonomic dysregulation does not result from a causal pathway or genetic pleiotropy, and these traits might therefore not be inevitably linked. Previously reported associations were likely confounded by the use of certain classes of antidepressants.

Heart and Brain Interaction of Psychiatric Illness: A Review Focused on Heart Rate Variability, Cognitive Function, and Quantitative Electroencephalography

Heart rate variability (HRV) reflects beat-to-beat variability in the heart rate due to the dynamic interplay of the sympathetic and parasympathetic nervous systems. HRV is considered an index of the functional status of the autonomic nervous system. A decrease in HRV is thus observed in individuals with autonomic dysfunction. Abnormal HRV has been reported in a range of mental disorders. In this review, we give an overview of HRV in patients with major depressive disorder (MDD), schizophrenia, and posttraumatic stress disorder (PTSD), one of whose core symptoms is cognitive dysfunction. The association between HRV and cognitive function is highlighted in this review. This review consists of three main sections. In the first section, we examine how HRV in patients with MDD, schizophrenia, and PTSD is characterized, and how it is different when compared to that in healthy controls. In the second section, beyond the heart itself, we discuss the intimate connection between the heart and the brain, focusing on how HRV interacts with quantitative electroencephalography (qEEG) in the context of physiological changes in the sleep cycle. Lastly, we finish the review with the examination of the association between HRV and cognitive function. The overall findings indicate that the reduction in HRV is one of main manifestations in MDD, schizophrenia, and PTSD, and also more generally HRV is closely linked to the change in qEEG and also to individual differences in cognitive performance.

The Efficacy of Playing Videogames Compared with Antidepressants in Reducing Treatment-Resistant Symptoms of Depression

Objective: The goal of this month-long controlled study was to compare the efficacy of a second antidepressant (sAD) medication with a prescribed regimen of Plants vs. Zombies™ (PvZ), a casual videogame, in reducing treatment-resistant depression symptoms (TRDS) and improving heart rate variability (HRV). Materials and Methods: Approximately ∼8 weeks after beginning antidepressant therapy, participants returned to psychiatrists for evaluation and complained of TRDS. The psychiatrist gave them a choice of self-selecting a sAD medication or playing a prescribed regimen of PvZ as part of a research study. Those who agreed were referred to researchers who then screened them for major depression, the criteria for inclusion. PvZ was prescribed four times per week for 30-45 minutes over 4 weeks. Self-reported data were collected at four different times utilizing the Patient Health Questionnaire-9. HRV, an indicator of autonomic nervous system (ANS) functioning, was also recorded each time. Results: The sAD group's TRDS significantly improved. Remarkably, the PvZ group's TRDS improved significantly beyond the control group at all measurement times except for time 1 or baseline. In addition, a single 30-minute session of playing PvZ was significantly more effective in acutely reducing TRDS when compared with the sAD group that surfed the NIHM website on depression. Changes in HRV parameters indicated increased parasympathetic engagement and ANS balance in the PvZ group compared with the sAD group. Discussion: The findings illustrate the potential of PvZ as an acute and chronic intervention for reducing TRDS. Health care practitioners such as physicians and recreational therapists can consider recommending a regimen of prescribed PvZ play as a method to ameliorate symptoms of depression for those clients who self-select this option. Finally, a psychophysiological method for measuring the efficacy of videogames in reducing TRDS and a means to quantify ANS changes during gameplay are presented.

Associations of depression severity with heart rate and heart rate variability in young adults across normative and clinical populations

Limitations of current depression treatments may arise from a lack of knowledge about unique psychophysiological processes that contribute to depression across the full range of presentations. This study examined how individual variations in heart rate (HR) and heart rate variability (HRV) are related to depressive symptoms across normative and clinical populations in 152 young adults (aged 18-35 years). Moderating effects of sex and antidepressant medication status were considered. Electrocardiogram data were collected during "vanilla" baseline and in response to positive and negative emotional cues. Linear regressions and repeated-measures mixed models were used to assess the relationships between Beck Depression Inventory-II (BDI-II) scores, sex, antidepressant use, and cardiovascular outcomes. Baseline models yielded significant main effects of BDI-II and sex on HR and significant interactions between antidepressant medication status and BDI-II on HRV outcomes. The main effects of BDI-II and sex on HR were no longer significant after controlling for cardiorespiratory fitness. Participants who denied current antidepressant use (n = 137) exhibited a negative association and participants who endorsed current antidepressant (n = 15) use exhibited a positive association between BDI-II scores and HRV. Emotional reactivity models were largely non-significant with the exception of a significant main effect of antidepressant medication status on high-frequency HRV reactivity. Results indicated antidepressant medication use may moderate the relationship between depression severity and cardiovascular functioning, but this requires replication given the modest proportion of medicated individuals in this study. Overall, findings suggest cardiovascular processes and cardiorespiratory fitness are linked to depression symptomatology and may be important to consider in depression treatment.

Predicting postictal suppression in electroconvulsive therapy using analysis of heart rate variability

BACKGROUND

Postictal suppression on an electroencephalogram (EEG) represents electrical silence during electroconvulsive therapy (ECT) and has been considered as a key feature associated with the efficacy of treatment. The present study aimed to predict postictal suppression using heart rate variability (HRV).

METHODS

Participants comprised 21 consecutive patients with depression who underwent bilateral pulse wave ECT. We analyzed the frequency domains of resting HRV before ECT. HRV indices such as the high-frequency component (HF) reflecting parasympathetic activity and the ratio of low-frequency component (LF)/HF reflecting sympathetic activity were natural log transformed for analysis. We evaluated ictal and peri-ictal EEG parameters and investigated their associations with HRV indices.

RESULTS

Postictal suppression and regularity were positively associated with ln[HF]. Postictal suppression remained significantly associated with ln[HF] after adjusting for age in multiple regression analysis of patients with depression.

LIMITATIONS

The present study could not examine the influence of diabetes mellitus, hypertension and polarity on HRV. In addition, the small sample size resulted in low statistical power.

CONCLUSIONS

These results suggested that ln[HF] before ECT could be utilized as a predictor of postictal suppression on EEG during ECT.

Heart rate variability changes in major depressive disorder during sleep: Fractal index correlates with BDI score during REM sleep

We investigated the relationship between autonomic nervous system activity during each sleep stage and the severity of depressive symptoms in patients with major depressive disorder (MDD) and healthy control subjects. Thirty patients with MDD and thirty healthy control subjects matched for sex, age, and body mass index completed standard overnight polysomnography. Depression severity was assessed using the Beck Depression Inventory (BDI). Time- and frequency-domain, and fractal HRV parameters were derived from 5-min electrocardiogram segments during light sleep, deep sleep, rapid eye movement (REM) sleep, and the pre- and post-sleep wake periods. Detrended fluctuation analysis (DFA) alpha-1 values during REM sleep were significantly higher in patients with MDD than in control subjects, and a significant correlation existed between DFA alpha-1 and BDI score in all subjects. DFA alpha-1 was the strongest predictor for the BDI score, along with REM density as a covariate. This study found that compared with controls, patients with MDD show reduced complexity in heart rate during REM sleep, which may represent lower cardiovascular adaptability in these patients, and could lead to cardiac disease. Moreover, DFA alpha-1 values measured during REM sleep may be useful as an indicator for the diagnosis and monitoring of depression.

Do Nonsuicidal Severely Depressed Individuals with Diabetes Profit from Internet-Based Guided Self-Help? Secondary Analyses of a Pragmatic Randomized Trial

INTRODUCTION

Diabetes mellitus type 1 and type 2 are linked to higher prevalence and occurrences of depression. Internet-based depression- and diabetes-specific cognitive behavioral therapies (CBT) can be effective in reducing depressive symptom severity and diabetes-related emotional distress. The aim of the study was to test whether disease-specific severity indicators moderate the treatment outcome in a 6-week minimally guided web-based self-help intervention on depression and diabetes (GET.ON Mood Enhancer Diabetes (GET.ON M.E.D.)) and to determine its effectiveness in a nonsuicidal severely depressed subgroup.

METHODS

Randomized controlled trial- (RCT-) based data (N = 253) comparing GET.ON M.E.D. to an online psychoeducation control group was used to test disease-specific severity indicators as predictors/moderators of a treatment outcome. Changes in depressive symptom severity and treatment response were examined in a nonsuicidal severely depressed subgroup (CES - D > 40; N = 40).

RESULTS

Major depressive disorder diagnosis at the baseline (p _prf6 = 0.01), higher levels of depression (Beck Depression Inventory II; p _prpo = 0.00; p _prf6 = 0.00), and lower HbA_1c (p _prpo = 0.04) predicted changes in depressive symptoms. No severity indicator moderated the treatment outcome. Severely depressed participants in the intervention group showed a significantly greater reduction in depressive symptom severity (d _prpo = 2.17, 95% Confidence Interval (CI): 1.39-2.96) than the control condition (d _prpo = 0.92; 95% CI: 0.001-1.83), with a between-group effect size of d _prpo = 1.05 (95% CI: 0.11-1.98). Treatment response was seen in significantly more participants in the intervention (4/20; 20%) compared to the control group (0/20, 0%; χ ² (2)(N = 40) = 4.44; p < 0.02). At the 6-month follow-up, effects were maintained for depressive symptom reduction (d _pr6f = 0.71; 95% CI: 0.19-1.61) but not treatment response.

CONCLUSION

Disease-specific severity indicators were not related to a differential effectiveness of guided self-help for depression and diabetes. Clinical meaningful effects were observed in nonsuicidal severely depressed individuals, who do not need to be excluded from web-based guided self-help. However, participants should be closely monitored and referred to other treatment modalities in case of nonresponse.

Increases in orbitofrontal cortex thickness following antidepressant treatment are associated with changes in resting state autonomic function in adolescents with major depression - Preliminary findings from a pilot study

In adults with major depressive disorder (MDD), effective treatment has been associated with increases in both heart rate variability (HRV) and cortical thickness. However, the impact of treatment on these indices has not yet been examined in adolescents. Cortical thickness and HRV were measured in twelve adolescents with MDD before and after 8 weeks of treatment with a selective serotonin reuptake inhibitor (SSRI). We examined treatment-related changes in depression symptoms, HRV, heart rate (HR), and cortical thickness, and analyzed correlations among these change indices. At follow-up, patients showed significantly decreased depression severity, increased HRV and increased thickness of the left medial orbitofrontal cortex (OFC). Clinical improvement was associated with increased HRV and decreased HR. Increased HRV was associated with increased cortical thickness of left lateral OFC and superior frontal cortex. Due to the small sample size, results represent preliminary findings that need replication. Further, in the absence of a placebo arm, we cannot confirm that the observed effects are due solely to medication. These preliminary findings suggest that SSRI treatment in adolescents impacts both cortical thickness and autonomic functioning. Confirmation of these findings would support OFC thickness and HRV as neurobiological mediators of treatment outcome.

Treatment with escitalopram modulates cardiovascular function in rats

Considering depression is three times more common in cardiac patients compared to the normal population and selective serotonin reuptake inhibitors (SSRI) as drug of choice for treating patients with cardiovascular disease and depression, our work aims to evaluate the cardiovascular effects of treatment for 21 days with escitalopram (5 mg/kg/day, ip) in rats. The treatment caused an increase in mean arterial pressure concomitant with a decrease in heart rate. Concerning heart rate variability, there was a significant reduction in the sympathetic component and an elevation of the parasympathetic component, indicating that escitalopram caused an autonomic imbalance with parasympathetic predominance. In addition, we observed a decrease in both low and very low frequency power in blood pressure variability. The cardiac autonomic blockade indicated an increase in parasympathetic modulation to the heart with escitalopram chronic treatment. However, no change was observed on baroreflex activity. On the other hand, there was a decrease in pressure response during acute restraint stress with no changes in the tachycardia response. These findings showed that despite the escitalopram be a relatively safe drug it can cause tonic effects on cardiovascular function as well as during aversive situations.

DSM-5 Criteria and Depression Severity: Implications for Clinical Practice

Background: Depression diagnosis requires five or more symptoms (Diagnostic and Statistical Manual of Mental Disorders-DSM-5). One of them must be either Depressed mood or Anhedonia, named main criteria. Although the secondary symptoms can be divided into somatic and non-somatic clusters, the DSM-5 identify depression in all or none fashion. In contrast, depression severity is a continuous variable. Therefore, it is commonly assessed with scales such as the Hamilton Depression Rating Scale (HAMD). Previously, we reported that patients with moderate depression (MD) exhibit greater impairments in cardiac-autonomic modulation than severely depressed (SD) patients. However, clinicians usually do not use scales. Objective: To verify whether the DSM-5 symptoms would be able to discriminate SD from MD and MD from non-depressed (ND) subjects. Material and Methods: Depression was diagnosed based on the Structured Clinical Interview for DSM-5® Disorders. The HAMD evaluated depression severity. In depressed subjects, MD and SD were defined considering the HAMD scores. ND was defined considering both the absence of DSM-5 criteria for depression and the HAMD score. Among 782 outpatients, 46 SD were found. MD and ND subjects were randomly sampled to match the demographic variables of the SD group. Results: Discriminant analysis showed that Depressed Mood was the most reliable symptom to discriminate ND from MD. Anhedonia discriminated SD from MD. Among the secondary DSM-5 criteria, the somatic cluster discriminated ND from MD and the non-somatic cluster SD from MD patients. Discussion: The presence of the somatic cluster in MD may indicate decreased vagal tone and/or increased sympathetic tone, leading to higher cardiovascular risk. As SD is associated with the non-somatic cluster, these patients are at risk of committing suicide. The DSM-5 symptoms exhibited by the patient may help the choice of adequate pharmacological treatment. This would avoid the use of antidepressants that unnecessarily increase cardiac risk in MD. When the symptom cluster suggests SD, the treatment must focus on the prevention of suicide. Conclusions: Depression severity may be inferred based on the DSM-5 criteria. The presence of the Anhedonia main criterium accompanied by non-somatic criteria indicate SD. The Depressive Mood criterium followed by somatic criteria suggest MD.

Heart rate variability and cordance in rapid eye movement sleep as biomarkers of depression and treatment response

OBJECTIVES

The relevance of rapid eye movement (REM) sleep in affective disorders originates from its well-known abnormalities in depressed patients, who display disinhibition of REM sleep reflected by increased frequency of rapid eye movements (REM density). In this study we examined whether heart rate variability (HRV) and prefrontal theta cordance, both derived from REM sleep, could represent biomarkers of antidepressant treatment response.

METHODS

In an open-label, case-control design, thirty-three in-patients (21 females) with a depressive episode were treated with various antidepressants for four weeks. Response to treatment was defined as a ≥50% reduction of HAM-D score at the end of the fourth week. Sleep EEG was recorded after the first and the fourth week of medication. HRV was derived from 3-min artifact-free electrocardiogram segments during REM sleep. Cordance was computed for prefrontal EEG channels in the theta frequency band during tonic REM sleep.

RESULTS

HRV during REM sleep was decreased in depressed patients at week four as compared to controls (high effect size; Cohen's d > 1), and showed a negative correlation with REM density in both, healthy subjects and patients at week four. Further, the fourteen responders had significantly higher prefrontal theta cordance as compared to the nineteen non-responders after the first week of antidepressant medication; in contrast, HRV at week one did not discriminate between responders and non-responders.

CONCLUSIONS

Our data suggest that HRV in REM sleep categorizes healthy subjects and depressed patients, whereas REM sleep-derived prefrontal cordance may predict the response to antidepressant treatment in depressed patients.

Intensified emotion perception in depression: Differences in physiological arousal and subjective perceptions

People suffering from depression perceive themselves and their surroundings as more negative than healthy ones. An explanation might be that depressed individuals experience negative information as more stressful than non-depressed subjects and, consequently, respond in an amplified manner on a subjective and physiological level. To test this proposition, we presented 41 patients with recurrent depressive episodes and 42 controls with stimuli from the International Affective Picture System split into three valence categories while different parameters of physiological arousal (e.g., heart rate variability) and subjective perceptions of valence and arousal were assessed. Furthermore, we examined social skills and emotional competence. Results regarding physiological arousal revealed an elevated skin temperature and a more accentuated respiratory frequency in depressed subjects. Furthermore, depressed subjects rated the stimuli as more negative and arousing, which was associated with reduced social and emotional competence. Variation in antidepressant medication, menstrual cycle and other factors that have an impact on HRV are a potential bias. Our findings suggest an intensified perception of negative emotion in depressed individuals as compared to controls that manifests itself in an increased physiological arousal as well as on a subjective level. This intensified emotion perception is further associated with deficits in social and emotional competence.

Physical Exercise for Late-Life Depression: Effects on Heart Rate Variability

OBJECTIVES

Late-life major depression is associated with increased cardiovascular risk and impaired autonomic control of the heart, as evident from reduced heart rate variability (HRV). Moreover, antidepressant drug therapy also might be associated with further reductions of HRV. In the SEEDS study, we investigated whether sertraline associated with physical exercise protocols led to improvements of HRV, compared with antidepressant drug therapy alone.

DESIGN

Single-blind randomized controlled trial.

SETTING

Psychiatric consultation-liaison program for primary care.

PARTICIPANTS

Patients aged 65-85 years with major depression, recruited from primary care.

INTERVENTIONS

Sertraline plus structured, tailored group physical exercise (S + EX) versus sertraline alone (S) for 24 weeks.

MEASUREMENTS

HRV indices (RR, percentage of NN intervals greater than 50 msec [pNN50], square root of the mean squared differences of successive NN intervals [RMSSD], standard deviation of heart rate [SDHR], standard deviation of the NN interval [SDNN], high-frequency band [HF], low-frequency band [LF], and their ratio [LF/HF]) were measured at baseline, week 12, and week 24. Psychiatric and medical assessments.

RESULTS

Participants displayed significant improvements of most HRV indices over time, irrespective of the group assignment (pNN50, RMSSD, SDHR, SDNN, HF, LF, and LF/HF). Moreover, patients in the S + EX group displayed greater increases of different HRV indices(RR, pNN50, RMSSD, SDHR, SDNN, HF, and LF) compared with those in the S group.

CONCLUSIONS

The combination of structured physical exercise and sertraline might exert positive effects on the autonomic control of the heart among older patients with major depression.

Reduced power spectra of heart rate variability are correlated with anxiety in patients with mild traumatic brain injury

Anxiety is one of the most frequently diagnosed emotional disorders after a mild traumatic brain injury (mTBI); however, predictors of anxiety after an mTBI remain uncertain. Recent research indicated that anxiety is associated with abnormalities in the autonomic nervous system (ANS) which can be evaluated by a power spectral analysis of heart rate variability (HRV). In this study, we investigated whether a frequency-domain analysis of HRV could correlate with the occurrence of anxiety in mTBI patients. We recruited 165 Taiwanese patients diagnosed with an mTBI and 82 volunteer healthy controls from three affiliated hospitals of Taipei Medical University during 2010-2014. The Beck Anxiety Inventory (BAI) was assessed at the 1st, 6th, and 12th weeks. We found that mTBI patients were more vulnerable to anxiety compared to healthy controls. The power spectral density of HRV was significantly lower in mTBI patients than in healthy controls. A correlation analysis indicated that anxiety was negatively significantly correlated with low- and high-frequency power at the 6th week. Our study suggests the clinical usefulness of HRV as a potential noninvasive tool for evaluating later anxiety in mTBI patients.

Influence diagram of physiological and environmental factors affecting heart rate variability: an extended literature overview

Heart rate variability (HRV) corresponds to the adaptation of the heart to any stimulus. In fact, among the pathologies affecting HRV the most, there are the cardiovascular diseases and depressive disorders, which are associated with high medical cost in Western societies. Consequently, HRV is now widely used as an index of health.

In order to better understand how this adaptation takes place, it is necessary to examine which factors directly influence HRV, whether they have a physiological or environmental origin. The primary objective of this research is therefore to conduct a literature review in order to get a comprehensive overview of the subject.

The system of these factors affecting HRV can be divided into the following five categories: physiological and pathological factors, environmental factors, lifestyle factors, non-modifiable factors and effects. The direct interrelationships between these factors and HRV can be regrouped into an influence diagram. This diagram can therefore serve as a basis to improve daily clinical practice as well as help design even more precise research protocols.

Differential Associations of Specific Selective Serotonin Reuptake Inhibitors With Resting-State Heart Rate and Heart Rate Variability: Implications for Health and Well-Being

OBJECTIVE

Debate has focused on the effects of the selective serotonin reuptake inhibitor (SSRI) antidepressants on heart rate (HR) and HR variability (HRV), both of which are predictors of adverse cardiovascular events. Here, we examine the associations between specific SSRI antidepressants and resting state HR (and HRV) after accounting for a host of potential confounding factors using propensity score techniques.

METHODS

Participants included 10,466 not taking antidepressants, 46 participants taking escitalopram, 86 taking citalopram, 66 taking fluoxetine, 103 taking paroxetine, and 139 taking sertraline. HR and HRV (root mean square of successive squared differences, high frequency) were extracted from 10-minute resting-state ECGs. Analyses including propensity score weighting and matching were conducted using R-statistics to control for potentially confounding variables.

RESULTS

Major findings indicated that users of all SSRI medications-except fluoxetine-displayed lower HRV relative to nonusers. Users of paroxetine also displayed significantly lower HRV relative to users of citalopram (Cohen's d = 0.42), fluoxetine (Cohen's d = 0.54), and sertraline (Cohen's d = 0.35), but not escitalopram. Although associations were also observed for HR, these were less robust than those for HRV.

CONCLUSIONS

Although paroxetine is associated with decreases in HRV relative to nonusers, as well as users of other SSRI medications, fluoxetine was the only medication not to display significant alterations in HR or HRV. These conclusions are limited by the cross-sectional design and nonrandomized nature of medication prescriptions. Findings highlight the importance of focusing on specific medications, rather than more heterogeneous groupings according to antidepressant action, and may have implications for health and well-being for the longer term.

Depression and cardiovascular disease: Epidemiological evidence on their linking mechanisms

Depression's burden of disease goes beyond functioning and quality of life and extends to somatic health. Results from longitudinal cohort studies converge in illustrating that major depressive disorder (MDD) subsequently increases the risk of cardiovascular morbidity and mortality with about 80%. The impact of MDD on cardiovascular health may be partly explained by mediating mechanisms such as unhealthy lifestyle (smoking, excessive alcohol use, physical inactivity, unhealthy diet, therapy non-compliance) and unfavorable pathophysiological disturbances (autonomic, HPA-axis, metabolic and immuno-inflammatory dysregulations). A summary of the literature findings as well as relevant results from the large-scale Netherlands Study of Depression and Anxiety (N=2981) are presented. Persons with MDD have significantly worse lifestyles as well as more pathophysiological disturbances as compared to healthy controls. Some of these differences seem to be specific for (typical versus 'atypical', or antidepressant treated versus drug-naive) subgroups of MDD patients. Alternative explanations are also present, namely undetected confounding, iatrogenic effects or 'third factors' such as genetics.

A literature review of heart rate variability in depressive and bipolar disorders

OBJECTIVE

Autonomic nervous system dysfunction has the potential to adversely impact general medical health and is known to exist in a number of psychiatric disorders. It reflects alterations in the function of several regions of the central nervous system. Measurement of heart rate variability provides a non-invasive tool for studying autonomic function. While the literature relating to the technical process of heart rate variability and aspects of depressive disorders has been reviewed in the past, research relating to both depressive and bipolar disorders has not been comprehensively reviewed. This paper critically considers the published research in heart rate variability in both depressive and bipolar affective disorders.

METHOD

A literature search using Medline, EMBASE, PsycINFO, ProQuest Psychology and references included in published literature was conducted using the following keywords: 'heart rate variability and autonomic, combined with depression, depressive disorder, bipolar, mania and sleep'.

RESULTS

The evidence demonstrates that, using heart rate variability measures, significant distortions of autonomic function are evident in both depressive and bipolar disorders and from most of their pharmacological treatments.

CONCLUSION

The autonomic dysfunction evident in both unipolar and bipolar affective disorders, and many psychotropic medications, has significant implications for our understanding of the neurophysiology of these disorders, their treatment and associated general health.

Resting respiratory sinus arrhythmia is related to longer hospitalization in mood-disordered repetitive suicide attempters

OBJECTIVES

Our aims were (1) to measure respiratory sinus arrhythmia (RSA), a high-frequency spectrum component of heart rate variability (HRV) in mood-disordered suicide attempters and (2) to investigate the relationship of RSA to symptoms and length of hospitalization.

METHODS

Forty-nine female repetitive-suicide attempters with depressive disorder or bipolar disorder were recruited in a general hospital setting. Manic or psychotic patients were excluded. Resting RSA values were calculated from electrocardiogram data, and severity of clinical presentation shortly after admission and length of hospital stay were assessed.

RESULTS

RSA was positively associated with a higher Beck Scale for Suicidal Ideation score (r = 0.33 P = 0.019). Stepwise multiple regression analysis showed a significant correlation between RSA and hospitalization length after adjusting other variables (beta coefficient = 3.00; P = 0.030). Patients with a higher resting RSA had more prolonged hospitalizations (hospitalization beyond 30 days) after controlling for other variables (odds ratio = 5.08, P = 0.017).

CONCLUSIONS

Interaction between the environment and the autonomic nervous system is complex. Further and more comprehensive research is needed.

Autonomic nervous system dysfunction in psychiatric disorders and the impact of psychotropic medications: a systematic review and meta-analysis

BACKGROUND

Autonomic nervous system (ANS) dysfunction is a putative underlying mechanism for increased cardiovascular disease risk in individuals with psychiatric disorders. Previous studies suggest that this risk may be related to psychotropic medication use. In the present study we systematically reviewed and analyzed published studies of heart rate variability (HRV), measuring ANS output, to determine the effect of psychiatric illness and medication use.

METHODS

We searched for studies comparing HRV in physically healthy adults with a diagnosed psychiatric disorder to controls and comparing HRV pre- and post-treatment with a psychotropic medication.

RESULTS

In total, 140 case-control (mood, anxiety, psychosis, dependent disorders, k = 151) and 30 treatment (antidepressants, antipsychotics; k = 43) studies were included. We found that HRV was reduced in all patient groups compared to controls (Hedges g = -0.583) with a large effect for psychotic disorders (Hedges g = -0.948). Effect sizes remained highly significant for medication-free patients compared to controls across all disorders. Smaller and significant reductions in HRV were observed for specific antidepressants and antipsychotics.

LIMITATIONS

Study quality significantly moderated effect sizes in case-control analyses, underscoring the importance of assessing methodological quality when interpreting HRV findings.

CONCLUSION

Combined findings confirm substantial reductions in HRV across psychiatric disorders, and these effects remained significant even in medication-free individuals. Reductions in HRV may therefore represent a significant mechanism contributing to elevated cardiovascular risk in individuals with psychiatric disorders. The negative impact of specific medications on HRV suggest increased risk for cardiovascular disease in these groups, highlighting a need for treatment providers to consider modifiable cardiovascular risk factors to attenuate this risk.

Selective serotonin reuptake inhibitors increase sympathetic activity under heavy alcohol exposure in rat models

AIMS

Self-medication with alcohol while being treated with antidepressants is a common problem in patients with depression. Both alcohol consumption and antidepressant administration can induce changes in the cardiac autonomic responses as indicated by heart rate variability (HRV). In this study, we examined cardiac autonomic responses induced by acute heavy alcohol exposure after SSRIs (selective serotonin reuptake inhibitors) medications.

MAIN METHODS

Rats were randomly divided into 3 groups, the alcohol administrated (Alc group), paroxetine administrated (SSRI group), and the SSRI+Alc group. Serum samples were collected to measure blood alcohol concentration (BAC). Physiological and cardiac autonomic responses including mean arterial pressure (MAP), heart rate (HR), and HRV were also compared among groups.

KEY FINDINGS

The SSRI group exhibited higher values of HRV and HF (high frequency) than did the Alc and SSRI+Alc groups after alcohol administration. In contrast to the Alc group, the SSRI+Alc group had significantly lower MAP than Alc group, and higher HR, standard deviation of NN-intervals (SDNN), SDNN to MRR ratio (CVNN), square root of the mean squared differences of the successive NN-intervals (RMSSD) and HF values after alcohol administration.

SIGNIFICANCE

Our results indicate that SSRIs increased sympathetic activity and alcohol reduced it in rats. The present study represents an attractive area for further research.

A preprocessing tool for removing artifact from cardiac RR interval recordings using three-dimensional spatial distribution mapping

Artifact is common in cardiac RR interval data that is recorded for heart rate variability (HRV) analysis. A novel algorithm for artifact detection and interpolation in RR interval data is described. It is based on spatial distribution mapping of RR interval magnitude and relationships to adjacent values in three dimensions. The characteristics of normal physiological RR intervals and artifact intervals were established using 24-h recordings from 20 technician-assessed human cardiac recordings. The algorithm was incorporated into a preprocessing tool and validated using 30 artificial RR (ARR) interval data files, to which known quantities of artifact (0.5%, 1%, 2%, 3%, 5%, 7%, 10%) were added. The impact of preprocessing ARR files with 1% added artifact was also assessed using 10 time domain and frequency domain HRV metrics. The preprocessing tool was also used to preprocess 69 24-h human cardiac recordings. The tool was able to remove artifact from technician-assessed human cardiac recordings (sensitivity 0.84, SD = 0.09, specificity of 1.00, SD = 0.01) and artificial data files. The removal of artifact had a low impact on time domain and frequency domain HRV metrics (ranging from 0% to 2.5% change in values). This novel preprocessing tool can be used with human 24-h cardiac recordings to remove artifact while minimally affecting physiological data and therefore having a low impact on HRV measures of that data.

Impact of Comorbid Depressive Disorders on Subjective and Physiological Responses to Emotion in Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) and unipolar depressive disorders (UDD) have been shown to differ from each other in dimensions of affective functioning despite their high rates of comorbidity. We showed emotional film clips to a community sample (n = 170) with GAD, GAD with secondary UDD, or no diagnosis. Groups had comparable subjective responses to the clips, but the GAD group had significantly lower heart rate variability (HRV) during fear and after sadness, compared to controls. While HRV in the GAD and control groups rose in response to the sadness and happiness clips, it returned to baseline levels afterwards in the GAD group, potentially indicating lesser ability to sustain attention on emotional stimuli. HRV in the GAD + UDD group changed only in response to sadness, but was otherwise unvarying between timepoints. Though preliminary, these findings suggest comorbid UDD as a potential moderator of emotional responding in GAD.

Effects of citalopram on heart rate variability in women with generalized anxiety disorder

BACKGROUND

Heart rate variability (HRV) is defined as variations in R-R interval with time. Dysautonomia is common in patients with psychiatric disorders such as depression and anxiety. Using HRV analysis, recent studies showed that in anxiety disorders, the vagal cardiac function decreases, and sympathetic function increases. This study aimed at investigating citalopram effects on HRV.

METHODS

This before and after study was conducted in 25 generalized anxiety disorder (GAD) patients. GAD was diagnosed based on clinical interview according to diagnostic and statistical manual of mental disorders IV-Text revised (DSM-IV-TR) criteria using Structured Clinical Interview for DSM Disorders-I questionnaire. A cardiologist studied 24 h ambulatory monitoring of the electrocardiogram (Holter) on all patients before the treatment. A volume of 20 mg of citalopram was administered to the subjects on a daily basis. Then, they were studied by Holter monitoring again after 1-month of administration of citalopram.

RESULTS

The average age of participants was 35.32 ± 8.7. The average Holter monitoring time was 23.29 ± 1.14 h before treatment and 23.81 ± 0.68 after it. The 3 h low frequency/high frequency ratio was significantly different between 3 h segments of time before treatment (P < 0.001). This difference was even higher after treatment (P = 0.001). Data showed an increase in parasympathetic tone during sleep both before and after treatment.

CONCLUSION

These patients showed some impairments of HRV indices that did not improve by citalopram in future, the clinical importance of such disturbances should be evaluated in details with prolonged follow-up and greater sample size.

Exploratory multivariate analysis of the effect of fatty fish consumption and medicinal use on heart rate and heart rate variability data

The overall aim of the present study was to explore the relationship between medicinal use and fatty fish consumption on heart rate variability (HRV) and heart rate (HR) in a group of forensic inpatients on a variety of medications. A total of 49 forensic inpatients, randomly assigned to a fish group (n = 27) or a control group (n = 22) were included in the present study. Before and by the end of the food intervention period HR and HRV were measured during an experimental test procedure. An additional aim of this paper is to show how multivariate data analysis can highlight differences and similarities between the groups, thus being a valuable addition to traditional statistical hypothesis testing. The results indicate that fish consumption may have a positive effect on both HR and HRV regardless of medication, but that the influence of medication is strong enough to mask the true effect of fish consumption. Without correcting for medication, the fish group and control group become indistinguishable (p = 0.0794, Cohen’s d = 0.60). The effect of medication is demonstrated by establishing a multivariate regression model that estimates HR and HRV in a recovery phase based on HR and HRV data recorded during psychological tests. The model performance is excellent for HR data, but yields poor results for HRV when employed on participants undergoing the more severe medical treatments. This indicates that the HRV behavior of this group is very different from that of the participants on no or lower level of medication. When focusing on the participants on a constant medication regime, a substantial improvement in HRV and HR for the fish group compared to the control group is indicated by a principal component analysis and t-tests (p = 0.00029, Cohen’s d = 2.72). In a group of psychiatric inpatients characterized by severe mental health problems consuming different kinds of medication, the fish diet improved HR and HRV, indices of both emotional regulation and physical health.

Peripheral heart action (PHA) training as a valid substitute to high intensity interval training to improve resting cardiovascular changes and autonomic adaptation

PURPOSE

The present study evaluated the effects of peripheral heart action training compared with high intensity interval training on changes in autonomic regulation and physical fitness.

METHODS

Eighteen young adults (9 women, 9 men) (age 24 ± 3 years, BMI of 22.67 kg/m(2), V'O2max 32.89 ml/kg/min) were randomly assigned to either a high intensity interval training group (n = 8) or a peripheral heart action training (PHA) group (n = 10). Before and after training, maximal whole-body muscular strength, time series of beat-to-beat intervals for heart rate variability, and baroreflex sensitivity were recorded. Arterial baroreflex sensitivity and heart rate variability were estimated on both time and frequency domains. Physical fitness level was evaluated with maximum oxygen consumption test.

RESULTS

The effects of PHA whole-body resistance training increased muscular strength and maximum oxygen consumption, with an effect on vagal-cardiac control and cardiovagal baroreflex sensitivity.

CONCLUSIONS

After 30 training sessions performed in 3 months, PHA resistance exercise promoted cardiovascular adaptations, with a decrease in the power spectral component of vascular sympathetic activity and an increase in the vagal modulation. Low-frequency oscillation estimated from systolic blood pressure variability seems to be a suitable index of the sympathetic modulation of vasomotor activity. This investigation also want to emphasize the beneficial effects of this particular resistance exercise training, considering also that the increase in muscular strength is inversely associated with all-cause mortality and the prevalence of metabolic syndrome, independent of cardiorespiratory fitness levels.

Investigating the Effect of Mindfulness Training on Heart Rate Variability in Mental Health Outpatients: A Pilot Study

Depression is associated with increased cardiac morbidity and mortality in people with and without cardiac risk factors, and this relationship is, in part, mediated by heart rate variability (HRV). Increased heart rate and reduced HRV are common in depressed patients, which may explain their higher cardiac risk. This pilot study investigated whether mindfulness-based cognitive therapy (MBCT) promoted objective changes in (1) HRV, and (2) depressive symptoms and quality of life, in mental health outpatients. Twenty-seven adults meeting criteria for DSM-IV Axis I disorders completed an 8-week MBCT program. Data were collected on three occasions, 8 weeks apart; twice before and once after MBCT. Participants completed the Short Form-36 and the Center for Epidemiological Studies Depression Scale (CES-D) at each test period. Heart rate and HRV were measured during electrocardiographic monitoring before and after a cognitive stressor. At baseline, 78% of participants met criteria for depression (CES-D ≥16). Multivariate analyses revealed a significant treatment effect for SF-36 physical summary score and depression (as a dichotomous variable), but not for HRV. This pilot study highlights the immediate psychological and health benefits of MBCT. Low power may have influenced the lack of a finding of an association between HRV and MBCT. However, the feasibility of the study design has been established, and supports the need for larger and longer-term studies of the potential physiological benefits of MBCT for cardiac health.

Autonomic dysfunction in mild cognitive impairment: evidence from power spectral analysis of heart rate variability in a cross-sectional case-control study

BACKGROUND

Mild cognitive impairment (MCI) is set to become a major health problem with the exponential ageing of the world's population. The association between MCI and autonomic dysfunction, supported by indirect evidence and rich with clinical implications in terms of progression to dementia and increased risk of mortality and falls, has never been specifically demonstrated.

AIM

To conduct a comprehensive assessment of autonomic function in subjects with MCI by means of power spectral analysis (PSA) of heart rate variability (HRV) at rest and during provocative manoeuvres.

METHODS

This cross-sectional study involved 80 older outpatients (aged ≥ 65) consecutively referred to a geriatric unit and diagnosed with MCI or normal cognition (controls) based on neuropsychological testing. PSA was performed on 5-minute electrocardiographic recordings under three conditions--supine rest with free breathing (baseline), supine rest with paced breathing at 12 breaths/minute (parasympathetic stimulation), and active standing (orthosympathetic stimulation)--with particular focus on the changes from baseline to stimulation of indices of sympathovagal balance: normalized low frequency (LFn) and high frequency (HFn) powers and the LF/HF ratio. Blood pressure (BP) was measured at baseline and during standing. Given its exploratory nature in a clinical population the study included subjects on medications with a potential to affect HRV.

RESULTS

There were no significant differences in HRV indices between the two groups at baseline. MCI subjects exhibited smaller physiological changes in all three HRV indices during active standing, consistently with a dysfunction of the orthosympathetic system. Systolic BP after 10 minutes of standing was lower in MCI subjects, suggesting dysautonomia-related orthostatic BP dysregulation.

CONCLUSIONS

Our study is novel in providing evidence of autonomic dysfunction in MCI. This is associated with orthostatic BP dysregulation and the ongoing follow-up of the study population will determine its prognostic relevance as a predictor of adverse health outcomes.

Heart rate variability characteristics in a large group of active-duty marines and relationship to posttraumatic stress

OBJECTIVE

Heart rate variability (HRV), thought to reflect autonomic nervous system function, is lowered under conditions such as posttraumatic stress disorder (PTSD). The potential confounding effects of traumatic brain injury (TBI) and depression in the relationship between HRV and PTSD have not been elucidated in a large cohort of military service members. Here we describe HRV associations with stress disorder symptoms in a large study of Marines while accounting for well-known covariates of HRV and PTSD including TBI and depression.

METHODS

Four battalions of male active-duty Marines (n = 2430) were assessed 1 to 2 months before a combat deployment. HRV was measured during a 5-minute rest. Depression and PTSD were assessed using the Beck Depression Inventory and Clinician-Administered PTSD Scale, respectively.

RESULTS

When adjusting for covariates, including TBI, regression analyses showed that lower levels of high-frequency HRV were associated with a diagnosis of PTSD (β = -0.20, p = .035). Depression and PTSD severity were correlated (r = 0.49, p < .001); however, participants with PTSD but relatively low depression scores exhibited reduced high frequency compared with controls (p = .012). Marines with deployment experience (n = 1254) had lower HRV than did those with no experience (p = .033).

CONCLUSIONS

This cross-sectional analysis of a large cohort supports associations between PTSD and reduced HRV when accounting for TBI and depression symptoms. Future postdeployment assessments will be used to determine whether predeployment HRV can predict vulnerability and resilience to the serious psychological and physiological consequences of combat exposure.